Textile bobbin



United States Patent Ofi" This invention relates to textile bobbins and, in particular, to wooden textile bobbins of the type used in introducing the filling or weft yarn in automatic looms.

It is the general object of the invention to provide an improved filling bobbin which is especially advantageous when weaving a fabric wherein the filling is comprised of compact, interlaced yarns.

It is a more specific object to provide a bobbin whose surface is unaffected by certain types of filling such as compact, interlaced yarns. i

It is a further object to provide a filling bobbin which is more resistant to abrasion, denting and crushing, and wherein swelling due to the high moisture conditions to which such bobbins are subjected is minimized.

It is a further object to provide a wooden textile bobbin having a tough, substantially integral finish contained entirely within the dimensions of the bobbin.

Another object is that of providing a wooden filling bobbin which is both physically and chemically resistant to certain specific types of treated compact, interlaced yarns.

A further important object is that of providing a bobbin which will minimize back tension particularly in the case of low denier, fiat filament, synthetic yarns such as nylon.

Other objects and advantages will become apparent from the following more detailed disclosure.

' Compact, interlaced multifilament yarns are coming into increasingly greater'usage in textiles and especially as a filling or weft yarn in the weaving of fabrics. United States Patent No. 2,985,995 discloses such a compact yarn which may be defined as a single or plied yarn essentially free from ring-like or other filament loops and wherein filament-to-filament spacing does not generally exceed one filament diameter, the filaments being randomly intermingled along the length thereof. Reference may be had to that patent for a more complete description of this type of yarn and its method of manufactures E. I. du Pont de Nemours & Co. manufacture such yarns which are known in the trade as Rotoset yarns. Examples of these are Dacron and nylon.

For some unexplainable reason whenever such a yarn is being fed as a filling yarn in automatic weaving from any presently known type of wooden bobbin regardless of the finish on the bottom invariably after a relatively short period of use a tacky, rubbery, mobile jell appears over the entire weaving surface of the bobbin. This jell formation takes place whether the bobbin has any of the conventional surface coatings such as lacquer, paint, enamels, baked or unbaked, varnish, etc., or whether the wood is impregnated with certain resins as disclosed in United States Patent No. 3,029,159, or whether the bobbin has been both impregnated and then surface coated. The bobbin cannot be used further in the weaving process unless the jell is removed and the surface of the bobbin is cleaned, thereby adding substantially to the weaving costs.

According to the present invention, the above disad vantages have been overcome by the provision of a bobbin whose surface is not susceptible to any reaction with these yarns. It has been found that wooden bobbins are subjected to impregnation with a specific class of resins, that is, those resins having reactive epoxy groups, and in the manner to be detailed hereinbelow, no adverse effects are noted upon the bobbins even after prolonged periods of usage. Additionally, the treated bobbin is provided with a tough, integral finish to render the' bobbin more durable and more highly resistant to physical abuse, while at the same time the surface of the bobbin is rendered smooth enough to feed therefrom the most delicate of yarns.

The invention generally comprises drying the wooden bobbins to a relatively low degree, preferably below about 7% by weight of moisture, then impregnating them: with a resin containing reactive epoxy or ethoxyline groups, then draining the excess and curing the resin in situ. During curing the bobbins are preferably tumbled or otherwise agitated in a manner to cause them to be further drained of excess impregnant and to prevent the formation of any beads or other localized deposits which may be cured in place.

The preferred resins are the epoxies which are characterized by reactive epoxy or ethoxyline groups The resin should be of relatively low viscosity, preferably below about 25 poise at 25 C. to facilitate its penetration into the wood. The viscosity of the more viscous resins may be reduced by the addition of monoepoxide or other reactive diluents that give off no volatile gases during the cure.

- Curing of the resin to a thermoset solid may be accomplished by the addition of amines, organic acids and anhydrides, borontrifiuoride amine complexes, amides containing reactive amine groups or by combinations of these various catalysts. The catalyst system is preferably one that will give a reasonably long pot life at room temperature and that will cure readily and completely at an elevated temperature. 7

EXAMPLE I Mols Epichlorohydrin 5.0

i I Bis-phenol A 0.5 NaOH (10% aqueous solution) 5.0

The temperature, after the intiial exotherm had taken place, was maintained at 75 C. for 80 minutes and then slowly raised over a 30-minute period to 105 C.'at which ilish a vacuum of about 25 inches of mercury. After Parts by wt. Above epoxy resin 52.2 Hexahydrophthalic anhydride 42.6 Butylglycidylether 5.2 Benzyld-ime-thylamine 0.3

The viscosity of this mix was 400 centipoise at 25 C. Bobbins were then prepared by drying to less than about 7% by weight of moisture, and preferably to about 3% or less by weight. These were loaded in a pressure type vessel from which air was then evacuated to estab- Patented Mar. 29, recs The resin was then' maintaining this vacuum for 15 minutes, the above formulation was admitted to a point where it covered the bobbins. The bobbins should remain covered during the entire impregnation period.

The pressure in the vessel was then increased to atmospheric after which the impregnant was permitted to permeate the wood for 15 minutes. The bobbins were then removed from the vessel and drained for two hours after which they were cured at 275 F. for one and one-half hours While tumbling.

The resulting bobbins contained 25% by weight of resin and had a Barcol hardness (Serial 4718) of between 40 and 55. After a 24-hour moisture absorption test in a 2% aqueous solution of Seyco 7 N (manufactured by Seydel-Woolley & Co., of Atlanta, Georgia), the weight gain was 16.8% while the dimension gain was 2.9% perpendicular to the grain and .'1% parallel to the grain.

These bobbins were tested in the weaving of Rotoset filling on a Unifil equipped loom wherein the bobbin cycle was repeated about every two hours so that the same bobbin was used in inserting filling about twelve times per day. After eight months under these same conditions these bobbins were not affected by the filling yarn and no tackiness or jelling appeared on the surface of the bobbins.

In the case of bobbins having the usual lacquer, baked enamel, varnish or synthetic resin finishes including polyester impregnated bobbins, after one week of weaving under the same conditions, tackiness and jelling appeared on the surfaces of all of these. Conventional bobbins which are presently used in weaving these compact, interlaced multifilament yarns must therefore be cleaned each week with a solvent or detergent and water and they must then be sanded and subjected to wire wooling to make them suitable for further use.

EXAMPLE II A further impregnation formula was prepared from the following ingredients:

Parts by wt. Epon 815 1 55.2 Hexahydrophthalic anhydride 44.8 Benzy-ldimethylamine 0.3

Epon 815 is a liquid epoxy resin comprised of diglycidyl ether of bis-phen0lA containing a diluent. It has an epoxiile equivalent of between 175 and 210, an average molecular weight of 340 to 400, and a viscosity at 25 C. of between 500 and 900 centipoise. It is manufactured by the Shell Chemical Corp., 920 Park Square Building, Boston, Mass.

The impregnation was carried out as set forth in Example I except that the cure is started at 170 F. and the temperature is increased as rapidly as possible to 285 F. The bobbins are tumbled for 2 hours at that temperature to complete the cure.

The resulting bobbins were found to contain between 27 and 28% of resin and had a Barcol hardness of between 50 and 55, approximately equal to the hardness of the cured resin itself and at least five times that of the wood itself prior to impregnation. When subjected to the standard Seyco test outlined above, the moisture gain was found to be 11.2% by weight, and a dimensional gain of 2.5% in a direction penpendicular to the grain and 4.6% parallel to the grain.

These bobbins were also tested under actual weaving conditions as in Example I and also indicated no tackiness or surface jelling after eight months of usage.

The amount of catalyst here may be varied from about 0.1 to 1.0 part by weight, the larger amounts resulting in more rapid cures but much shorter pot lives. Gther tertiary amines may be employed as catalyst.

This class of epoxy resin may be cured with other anhydrides such as methyl nadic anhydride or dodecyl succinic anhydride. Straight amine catalysts with primary, secondary or tertiary amines may be used but with extremely limited pot life. Also latent catalysts such as boron trifluoride amine complexes may be employed.

4 EXAMPLE 111 Parts by wt. Kopoxite 159 1 Diglycidyl ether 5 Borontrifluoride monoethylamine 5 1 Kopoxite 159 is a liquid epoxy resin comprised of resorcinol diglycidyl ether with an epoxide equivalent of 12S, molecular weight of 222.2 and viscosity of 500 centipoise at 25 211321 is manufactured by Koppers Company, Inc., Pittsburgh The impregnation and cure were carried out as in Example I and produced bobbins having a 30.8% resin content, Barcol hardness of 55, and a moisture gain of 8.4% by weight in a Seyco test with a 2.3% dimensional gain perpendicular to the grain and 4.0% parallel to the grain.

This formulation has a pot life in excess of three weeks. The amine complex may be used in ratios of from 1 to 10 parts per hundred parts of resin.

Here, again, bobbins showed no tackiness or jelling with Rotoset yarns after about eight months of weaving.

All of the following formulae also produced equally satisfactory impregnated bobbins as indicated from actual tests:

EXAMPLE N Parts by Wt. Epoxide 201 1 Borontrifiuoride monoethylamine 3 Epoxide 201 is 3,4-epoxy-6-methylcyclohexylmethyl 3,4 epoxy-G-n1et11ylcycl0hexane carboxylate with a molecular weight of 280.85 and a viscosity of 1810 centipoise at 25 C. and is manufactured by Union Carbide Chemicals 'Co., 30 E. 42nd St, New York, N.Y.

The impregnation and cure were carried out as in Example I and produced bobbins having a 20% resin content by weight and Barcol hardness of 55. The Standard Seyco test showed a 6.0% by weight moisture gain, 1.8% dimensional gain perpendicular to the grain and 3.2% parallel to the grain.

EXAMPLE VI Parts by wt. Epon RL 1062 1 98 Diethylenetriamine 2 1 Epon RL 1062 is an aliphatic based epoxy resin having an epoxide equivalent of to 165, molecular weight of 300, and viscosity of between and 210 at 25 C. and is manufactured by the Shell Chemical Co.

Impregnation and cure were carried out as in Example I but at 300 F. and produced bobbins having a 35% by weight resin content, Barcol hardness of 30 and which showed a 21% by weight moisture gain in the Standard Seyco test.

EXAMPLE VII Parts by wt. BR 18795 (ERL 2795) 1 55.2 Hexahydrophthalic anhydride 44.8 Benzyldimethylamine 0.2

BR 18795 (ERL 2795) is an epoxy resin having an epoxy equivalent of 179 to 19-1, molecular weight of 340 to 400 and a viscosity of between 500 and 900 centipoise at 25 C. and is manufactured by Union Carbide Chemicals Co.

Bobbins were impregnated with this resin and cured at 250 F. for 1 /2 hours with tumbling. The bobbins were found to have a resin content of 32%, Barcol hardness of 60, and showed a moisture gain of 13.3% by weight in the Seyco test.

EXAMPLE VIII Parts by wt. BR 18795 85 Butyldiglycidylether 15 Borontrifluoride monoethylamine 3 Bobbins were impregnated and cured with this formulation by being tumbled for 1 hour at 260 F. and then baked at 8 hours at the same temperature. The bobbins possessed a resin content of 30%, Barcol hardness of 20, and showed a moisture gain of 18.1% by weight in the Seyco test.

EXAMPLE IX Parts by wt. Epon 815 51.6 Methylnadic anhydride 48.4 Benzyldimethylamine 0.2

Bobbins were impregnated and cured with this formula at 260 F. for 1 /2 hours with tumbling and were found to possess a resin content of 25% and Barcol hardness of 60.

EXAMPLE X Parts by wt. Kopoxite 159 57 Methylnadic anhydride 43 ot-Met'nylbenzyldimethylamine 0.3

Curing with this formulation was effected at 260 F. for 2 hours with tumbling. The bobbins indicated a resin content of 21% and Barcol hardness of 50.

EXAMPLE XI Parts by wt. Kopoxite 159 50 Hexahydrophthalic anhydride 50 u-Methylbenzyldimethylamine 0.3

Curing took place as in Example X and the treated bobbins showed a resin content of 25% and Barcol hardness of 50. The Seyco test showed a moisture pick up of 13.6% by weight.

In addition to their particular resistance to the deleterious effects imparted to conventional bobbins by compact, interlaced multifilament yarns, bobbins impregnated with epoxy resins as set forth in the examples above were found to resist abrasion and blows which would cause nicks and dents in unimpregnated or surface coated bobbins. Resistance to crushing was found to increase very substantially, particularly against the relatively high contractile forces exerted by low twist yarns.

An extremely important advantage of these epoxy impregnated bobbins resides in the very low back tension imparted to flat filament, synthetic yarns such as nylon, due apparently to the low coefiicient of friction of the surface of these bobbins. The back tension has been found to be lower than that from any known bobbin surface including those with lacquer or varnish finishes. This low back tension effectively eliminates puckering of woven fabric attributed to stretching of the filling yarn during insertion thereof into the loom shed which has been frequently encountered with synthetic yarns.

Further, as noted above, bobbins treated according to the present invention have a fairly low propensity for water absorption.

While in the examples given above, curing takes place at elevated temperatures, it is to be understood that this can be effected at room temperatures with the use of certain catalysts such as, for example, the primary, secondary, or tertiary amines.

Also, the ratio of resin to reactive diluent may be varied over a relatively large range with advantageous results, and as noted in certain of the examples, the catalyst concentration may vary between about one and ten parts per hundred parts of impregnant solution.

The bobbins for maximum results should have a resin content of at least about 10% by weight and preferably greater than about 20% by weight.

While one embodiment and modifications of the invention have been disclosed, it is to be understood that the inventive concept may be carried out in a number of ways. This invention is, therefore, not to be limited to the precise details described, but is intended to embrace all variations and modifications thereof falling within the spirit of the invention and the scope of the claims.

We claim:

1. A wooden textile bobbin the wood of which has been dried to less than about 7% by weight of moisture and then impregnated with a non-aqueous solution comprising a major portion of a synthetic resin having reactive epoxy groups and a catalyst, said resin having been cured in situ, the bobbin surface being rendered non-reactive to compact, interlaced yarns.

2. A wooden textile bobbin the wood of which has been dried in less than about 3% by weight of moisture and then impregnated with a non-aqueous solution comprising a major portion of a synthetic resin having reactive epoxy groups and a catalyst, said resin having been cured in situ, the bobbin surface being rendered nonreactive to compact, interlaced yarns.

3. A wooden textile bobbin the wood of which has been dried to less than about 7% by weight of moisture and then impregnated with a non-aqueous solution comprising a major portion of a synthetic resin having reactive epoxy groups and a catalyst, said resin having been cured in situ, said bobbin having a resin content of at least about 10% by weight, the bobbin surface being rendered non-reactive to compact, interlaced yarns.

4. A wooden textile bobbin the wood of which has been dried to less than about 7% by weight of moisture and then impregnated with a non-aqueous solution consisting essentially of a synthetic resin having reactive epoxy groups, a diluent and a catalyst, said resin having been cured in situ, the bobbin surface being rendered non-reactive to compact, interlaced yarns.

5. A wooden textile bobbin the wood of which has been dried to less than about 7% by weight of moisture and then impregnated with a non-aqueous solution comprising a major portion of a synthetic resin having reactive epoxy groups, a diluent and a catalyst, said resin having been cured in situ, said bobbin having a resin content of at least 10% by weight.

References Cited by the Examiner UNITED STATES PATENTS 2,041,841 5/1936 Lanz 13920 2,715,916 8/1955 Nelson 13920 3,029,159 4/1962 Bliven et al. 117--59 3,077,420 2/ 1963 Kenaga 117-59 MERVIN STEIN, Primary Examiner.

G. F. MAUTZ, Assistant Examiner. 

1. A WOODEN TEXTILE BOBBIN THE WOOD OF WHICH HAS BEEN DRIED TO LESS THAN ABOUT 7% BY WEIGHT OF MOISTURE AND THEN IMPREGNATED WITH A NON-AQUEOUS SOLUTION COMPRISING A MAJOR PORTION OF A SYNTHETIC RESIN HAVING REACTIVE EPOXY GROUPS AND A CATALYST, SAID RESIN HAVING BEEN CURED IN SITU, THE BOBBIN SURFACE BEING RENDERED NON-REACTIVE TO COMPACT, INTERLACED YARNS. 